Take a heavy-bottomed pan (dutch oven, etc.) and 1 T. olive oil. Roast corn over flame in pan until it is slightly browned. (This will take longer if you start with frozen.) Remove corn and set aside.
Now roast the eggplant in another 1 T. olive oil and some salt until it darkens and any juice boils down, stirring every few minutes. (This will take 8-10 minutes.) Remove eggplant and set aside.
Finally, use last 1 T. oil to brown the onions and garlic. As onions begin to soften, add the cayenne, chili, and cinnamon. You know you are ready for the next step when the aromas begin to soften.
Add the black beans, tomatoes, and broth. Wait until the mixture gets hot enough to melt the chocolate, then add the lime and chocolate.
Return the eggplant and corn to the chili and serve.